Beading tool, housing part for an electrochemical cell and method for treating a housing part

Abstract

Beading tool (1) for beading a workpiece (10), wherein - the beading tool (1) has a contact surface (2) which is designed to interact with the workpiece (10), wherein the contact surface (2) has a plurality of local, mutually delimited elevations (4), - a dimension of the elevations (4) is smaller than a width of the contact surface (2); the elevations (4) are randomly distributed and / or irregularly arranged.

Description

[0001] The present application relates to a beading tool for beading a workpiece, a housing part for an electrochemical cell, an electrochemical cell and a method for treating a housing part.

[0002] US Patent No. 2,024,803 A discloses machines with two beading wheels for beading pipes. GB Patent No. 793,923 A discloses beading tools with a beading wheel and a counterpart with a recess.

[0003] A bead in connection with an electrochemical cell is described, for example, in DE 103 32 093 A8 and US 7 495 889 B2.

[0004] One problem to be solved is to provide an improved beading tool, an improved housing part for an electrochemical cell and means for treating and / or producing an improved housing part and / or an electrochemical cell.

[0005] This problem is solved by the features of the independent patent claims. Advantageous embodiments and further developments are the subject of the dependent patent claims.

[0006] A proposed beading tool is intended for beading a workpiece. The beading tool has a contact surface designed to interact with the workpiece, wherein the contact surface has a plurality of local, distinct elevations. The contact surface is preferably designed such that, during the aforementioned interaction or beading of the workpiece, it forms or defines an indentation or bead, i.e., a groove-shaped depression in the workpiece. The workpiece is, for example, a housing or housing part of an electrochemical cell. The tool is expediently made of a deformable material, for example, a metal.

[0007] The elevations are preferably arranged and designed to form depressions in the workpiece during the beading process, for example in the said bead, which depressions largely correspond in shape and size to the elevations of the contact surface of the beading tool.

[0008] In a housing part, for example, an electrochemical cell such as an electrolytic capacitor, beads are preferably used for radial bracing, for example, a capacitor winding relative to the housing or housing part. With the help of the bead, the capacitor winding can be held or braced preferably from several sides, for example, axially and radially.

[0009] A further aspect of the present application relates to a housing part for an electrochemical cell, for example a housing. The housing part defines a cavity and has at least one recess, wherein a plurality of local depressions are formed in the recess. The recess is preferably a bead.

[0010] The housing part has preferably been beaded or treated using the beading tool as described above.

[0011] Preferably, the housing part is cup-shaped with one open side and one side closed, for example with a lid.

[0012] The beading tool can advantageously form the housing part with the indentation and the plurality of local depressions, for example, during production or treatment. The local depressions are preferably delimited from one another.

[0013] Due to the local recesses in the housing part's indentation, a housing part can be connected to an electrode stack or fixed relative to it, particularly during the manufacture or assembly of an electrochemical cell, for example an electrolytic capacitor, in such a way that the electrochemical cell can withstand particularly high vibration loads and / or shock loads without being damaged. In particular, the provision of the local recesses can particularly efficiently prevent relative movement of the electrode stack in the axial direction relative to the housing part, thus also preventing internal electrical contact interruptions or damage in the electrochemical cell, particularly in automotive applications of the electrochemical cell.

[0014] In a preferred embodiment of the housing part, the indentation extends over the entire circumference of the housing part. This embodiment can particularly advantageously prevent a preferably axial relative movement of the aforementioned electron stack relative to the housing part (or vice versa).

[0015] In a preferred embodiment of the housing part, the indentation is not a compression bead.

[0016] One dimension of the elevations is smaller than a width of the contact surface. This configuration allows a surface of the above-mentioned bead or indentation to be made particularly large, for example compared to an indentation with a smooth surface and without the elevations according to the invention. The large number of locally separated depressions in the indentation of the housing part advantageously allows deformations of the housing part, for example during the beading of the housing part, to be formed in the smallest possible space, whereby external dimensions of the housing part, for example a length of the housing part, are not or only very slightly influenced or increased. Furthermore, after the beading of the housing part or workpiece, springback, for example of a wall of the housing part, when the beading tool is removed, can be prevented.

[0017] Furthermore, the inventive recesses in the indentation of the housing part advantageously allow a bead to be formed in which plastic material deformation or material displacement preferably occurs not toward the bead edge but significantly within the bead itself, thus partially counteracting a thinning of the bead, particularly at the bead edge. This advantageously has less influence on external dimensions, such as the length, of the housing part.

[0018] In a preferred embodiment of the beading tool, the elevations have elevation surfaces with a surface area between 0.1 mm 2 and 1 mm 2 Preferably, each elevation has an elevation area with a surface area between 0.1 mm 2 and 1 mm 2 on.

[0019] In a preferred embodiment of the beading tool, the distance between adjacent elevations is greater than 0.5 mm.

[0020] The elevations are randomly distributed and / or irregularly arranged. This design advantageously allows the beading of the workpiece to be carried out particularly effectively, whereby, in particular, regular deformation ("gear coupling") of the housing part or the respective workpiece by the beading tool during the interaction between the beading tool and the housing part can be prevented.

[0021] In a preferred embodiment of the beading tool, the individual elevations have different diameters and / or dimensions.

[0022] In an advantageous embodiment of the beading tool, the beading tool is a beading wheel or a beading roller. This design enables a particularly effective beading or treatment of the housing part or workpiece, so that, in particular, the indentation or bead can be formed over the entire circumference of the housing part (see above).

[0023] In a preferred embodiment of the housing part, it has a main axis, wherein the indentation is a first indentation, and wherein the housing part has a second indentation arranged axially offset from the first indentation. The second indentation is preferably of the same type as the first indentation.

[0024] Two axially offset indentations typically complicate the axial fixation of the housing part relative to a housed electron stack. In particular, by forming the second bead in a conventional beading or beading process, the tension resulting from the first bead can be relieved by the second bead.

[0025] This problem can be solved in particular by the beading according to the invention, wherein the indentation of the housing part has a plurality of local depressions in connection with the last-mentioned embodiment.

[0026] A further aspect of the present application relates to an electrochemical cell comprising the housing part, wherein an electrode stack is arranged or accommodated in the housing part, and wherein the at least one indentation fixes the electrode stack relative to the housing part.

[0027] In a preferred embodiment of the electrochemical cell, it is designed according to an electrolytic capacitor, wherein the electrode stack is a capacitor winding comprising electrode foils and an electrolyte in contact with the electrode foils.

[0028] In a preferred embodiment of the electrochemical cell, the electrolytic capacitor is an aluminum electrolytic capacitor having an anode made of aluminum or comprising mainly aluminum.

[0029] A further aspect of the present application relates to a method for treating a housing part. The method comprises providing a housing part and a beading tool, as well as providing the housing part with a bead using the beading tool such that a plurality of local, mutually delimited depressions are formed in the bead. The method allows the housing part to be expediently formed with the plurality of local depressions, so that the aforementioned advantages for the housing part and / or the electrochemical cell can be utilized.

[0030] The recesses of the housing part are preferably caused by the elevations of the beading tool.

[0031] In a preferred embodiment of the method, when providing the housing with the bead, a contour of the bead and / or the recesses are embossed into the housing part by means of a coarse beading tool in a first processing step.

[0032] In a preferred embodiment of the method, when the housing is provided with the bead, the recesses are defined in a subsequent processing step using a fine beading tool.

[0033] The term “contour” of the bead preferably refers to a bead which only has contours of the recesses, these contours being defined by the said subsequent processing step with the fine beading tool according to their desired final shape.

[0034] Alternatively, the term “contour” can refer to a smooth surface of the bead.

[0035] In a preferred embodiment of the method, the method is a method for producing an electrochemical cell, wherein an electrode stack is provided before the housing part is provided with the bead and this electrode stack is inserted into the housing part, wherein the electrode stack is fixed in the housing part by providing the bead.

[0036] In a preferred embodiment of the method, after the electron stack has been inserted into the housing part, the latter is first deformed until the housing part touches the electron stack, wherein the housing part is then provided with the bead.

[0037] Due to the beading or treatment of the housing part, a corresponding device is expediently also necessary, in which, for example, a beading wheel or beading tool is received and in which this is fixed relative to the housing part and / or the electrochemical cell.

[0038] Before treating the housing part or before providing the housing part with the bead or indentation according to the invention, including the plurality of local depressions, the housing part can first be pre-beaded with a conventional bead in a previous process step, for example, comprising a smooth bead surface without depressions. Subsequently, the said housing part can be provided with the bead, including the plurality of local depressions, according to the invention.

[0039] The electrochemical cell described above is preferably treated, treatable, or producible by the method described here. In particular, all features disclosed for the method can also relate to the electrochemical cell, the beading tool, and / or the housing part, and vice versa.

[0040] Further advantages, advantageous embodiments and expediencies of the invention will become apparent from the following description of the embodiments in conjunction with the figures. The Fig. 1A, Fig. 1B and Fig. 1C each show an electrochemical cell. Fig. Figure 2A schematically indicates a perforation of a housing part of an electrochemical cell. Fig. 2B schematically indicates a deformation of a housing part. Fig. 3 shows schematically a bead wheel according to the invention. Fig. 4 indicates a deformation of a housing part according to the invention. The Fig. 5A to 5F schematically indicate a beading of a housing part according to the invention.

[0041] Identical, similar, and functionally identical elements are provided with identical reference numerals in the figures. The figures and the relative sizes of the elements depicted in the figures are not to be considered to scale. Rather, individual elements may be exaggerated for clarity and / or clarity.

[0042] Fig. 1A shows a conventional electrochemical cell 100. The electrochemical cell 100 is preferably an electrolytic capacitor, for example, an aluminum electrolytic capacitor. The electrochemical cell 100 has a major axis X. Along the major axis, the electrochemical cell has a length L. The electrochemical cell 100 further comprises a housing or housing part 10. In addition, the electrochemical cell 100 has an electrode stack 20. The electrode stack can be a capacitor winding. The electrode stack 20 has electrode foils 21. Furthermore, the electrode stack 20 or the electrochemical cell 100 expediently has an electrolyte (not explicitly shown). According to the Fig. 1A, the electrochemical cell 100 has a smooth housing wall or surface without indentations, at least in the area of ​​the electrode stack 20. This allows, for example, the electrode stack 20 to move relative to the housing part 10 under sufficient shock or vibration loads, which can simultaneously impair the function of the electrochemical cell.

[0043] In Fig. 1B is, in contrast to the Fig. 1A, the housing part 10 is beaded or has a bead or indentation 6. The indentation 6 preferably runs along the entire circumference of the housing part 10. The indentation 6 can be arranged circumferentially around the housing part 10. As a result, the housing part 10 can be fixed or axially clamped relative to the electrode stack 20. With the aid of the indentation 6, the electrode stack 20 can preferably be held or clamped in several directions, for example axially and radially (as indicated by the double arrows in Fig. 1B).

[0044] Without the indentation 6, the electrode stack is held only by the axial bracing between a top and a bottom (parts not explicitly marked) of the housing part 10. With the indentation 6, however, the electrode stack is held from all sides and / or, in particular, is clamped or fixed axially and radially.

[0045] In Fig. 1C, the housing part 10 of the electrochemical cell 100 is provided with two indentations 6, which are arranged axially offset from one another, whereby a tension of the electrode stack 20 relative to the housing part 10 or other properties of the electrochemical cell 100 can be further improved under certain circumstances.

[0046] In Fig. 2A, a part of a beading tool 1 is indicated in a lateral view, wherein the beading tool 1 is connected to a housing part 10 of an electrochemical cell (cf. Fig. 1A to 1C) during a conventional beading process. The beading tool 1, preferably a beading wheel, has a contact surface 2. The beading wheel 1 interacts with the housing part 10 via the contact surface 2. The Fig. 2A preferably shows a side or cross-sectional view of the mentioned components. The curved arrows indicate Fig. 2A indicates that in the beading shown, either the housing part 10 or the beading tool, or both parts, are rotated and / or driven after they have been brought into mechanical contact with each other. The housing part 10 is deformed or squeezed in a contact area KB of the housing part 10. Accordingly, the housing part 10 is expediently made of a deformable material, for example, a metal. In the contact area KB, the beading wheel 1 interacts mechanically with the housing part 10.

[0047] In Fig. 2B schematically shows the above-mentioned contact area KB from a different perspective as well as areas of the housing part 10. The large arrow pointing to the left in the contact area KB indicates a direction of movement BR of the beading tool 1 (compare Fig. 2A) on the housing part 10. The small arrows pointing from the inside of the contact area KB on the left side thereof to an edge of the contact area KB indicate a material displacement or plastic deformation of the material of the housing part 10 (compare Fig. 2A).

[0048] During the described beading process, the beading tool 1 presses directly onto the housing part and indirectly onto the electrode stack described above (in Fig. 2A not explicitly marked). In the process, the housing part and the electrode stack 20 deform, preferably both irreversibly (plastically) and reversibly (elastically). After the beading or after the housing part 10 is no longer in mechanical contact with the beading tool 1 and / or exerts a force on it, the housing part 10 or a wall thereof springs back and a holding diameter, i.e. an inner diameter of the housing part 10 in the indentation becomes larger, e.g. from 22.2 mm during beading to 22.6 mm afterwards. The elastic deformation of the electrode stack 20 is sufficient to follow this expansion of the housing part, so that the housing part 10 holds or fixes the electrode stack 20.The disadvantage here is that during this springback or relaxation, the mechanical forces between the electrode stack 20 (see above) and the housing part 10 become smaller, so that the electrochemical cell 100 can be stable “only” up to approximately 30 g, for example, during vibration loading or acceleration.

[0049] A further disadvantage is a material thinning of the housing part 10. During the described beading, the housing part 10 becomes thinner at the point where it interacts with the beading tool 1 (material displacement) with the result that it also becomes longer (see length L in the Fig. 1A to 1C).

[0050] After several rotations during the crimping process, extensions of typically 0.2 mm can occur. This housing extension is detrimental to the fixation of the electrode stack or capacitor winding in the housing part 10, as it reduces the axial holding forces. Consequently, the vibration load capacity in the axial direction is also reduced. A second axially offset indentation 6 can even loosen the tension resulting from the first indentation 6.

[0051] Based on the following Fig. 3, 4, and 5A to 5F, the inventive beading of a housing part 10 for an electrochemical cell as described above using a beading tool according to the invention, or a housing part 10 of the electrochemical cell 100 treated accordingly with the beading tool, will now be described. The aspects described above in connection with the electrochemical cell can also relate to the subject matter of the present invention described below.

[0052] Fig. 3 schematically shows a representation of a contact surface of a beading tool 1 according to the present invention. The beading tool 1 can be a beading wheel or a beading roller. The beading tool 1 has a contact surface 2. The contact surface 2 is preferably designed to interact with a workpiece, for example, a housing part of an electrochemical cell (see above). The contact surface 2 can be arranged circumferentially around the beading tool 1, for example, circumferentially. The contact surface 2 has a plurality of elevations 4. The elevations 4 are local and delimited from one another. The elevations 4 can be spaced from an edge (not explicitly marked) of the contact surface 2. Furthermore, the elevations each have elevation surfaces 8. The elevation surfaces 8 preferably represent surfaces of the elevations perpendicular to the elevation direction. The elevation surfaces 8 preferably have a surface area between 0.1 mm 2and 1 mm 2 Alternatively, the area of ​​the raised surfaces 8 can be less than 0.1 mm 2 , for example 0.01 mm 2 , or larger than 1 mm 2 , for example 10 mm 2 , be. In addition, the distances between adjacent elevations are preferably greater than 0.5 mm (distances not explicitly marked). A dimension of the elevations 4 is preferably smaller than a width B of the contact surface 2. Preferably, the elevations 4 are furthermore randomly distributed and / or irregularly arranged.

[0053] Fig. Figure 4 schematically indicates a deformation of the housing part 10 according to a beading according to the invention. The housing part 10 is not shown as a whole, but only in the form of certain areas (cf. reference numeral 10 in Fig. 3). Furthermore, the elevations 4 of the beading tool 1 are shown, which are arranged irregularly next to one another. The indentation 6 is indicated by the horizontal lines. Due to the design of the elevations 4, a deformation or displacement of the material of the housing part 10, which without the elevations mainly occurs towards the edge of the indentation 6, i.e. in the direction of the main axis X, is also achieved within the indentation 6 (cf. vertical and horizontal arrows on the elevations 4), so that a material thinning of the housing part 10 at the edge of the indentation can be at least partially counteracted. The "splitting" effect that emanates from a normal smooth beading tool can be advantageously prevented here, because the Fig. The areas of the housing part 10 marked with 4 between the elevations 4 counteract the splitting or thinning of the housing part 10. The size and shape of the elevations 4 allow for the formation of many small deformations and thus also help to limit or prevent the aforementioned springback of the housing part 10 after sinking. The reason for this is that a single small deformation causes a relatively smaller springback or spring relaxation.

[0054] In other words, the deformation of the housing part is not caused by a large force area or crushing area, but by the many small raised surfaces 8 (cf. Fig. 3). This results in less impact on the external dimensions of the housing part 10, particularly the length L, and in particular increases them. Furthermore, large-scale springback when removing the beading wheel is avoided (see below). In contrast to a conventional beading, for example with a smooth bead or indentation, the invention may require more revolutions of the beading tool to properly emboss the indentation and its depressions into the housing part. This process can also be referred to as a type of "peening."

[0055] The Fig. 5A to 5F illustrate the inventive treatment of a housing part 10 of an electrochemical cell 100 as described above, in particular the beading of the housing part, for example, during the manufacture of the electrochemical cell. In each case, a contour of the housing part 10 is visible, which is created during the process for beading the housing part 10 or providing the housing part with a bead or indentation 6 according to the invention.

[0056] In the Fig. 5A to 5F is the electrode stack to be fixed axially to the housing part 10 by the indentation 6 (cf. Fig. 1A to 1C) are not shown for clarity. In Fig. 5A, the housing part 10 has only been provided with a conventional recess 6 with a smooth surface (see also Fig. 1A to 1C). Depending on the shape of the bead 6, one must imagine an exterior space of the housing part 10 on the left side of the housing part 10 or its contour, and an interior space or cavity (not explicitly marked) of the housing part 10 on the right side. The dashed line or contour indicates the position of the housing part 10 during the treatment process or during beading. This line or contour defines a minimum diameter of the housing part 10 or the contour, whereas the solid line indicates springback and / or a holding diameter (see above). This also applies to the other figures.

[0057] In Fig. 5B is a beading process according to the invention with a beading tool according to the invention (cf. Fig. 3) has been applied to the housing part 10, so that two recesses 5 are already embossed in the shown cross-section or area of ​​the housing part 10. The size and shape of the recesses 5 preferably correspond substantially to the size and shape of the elevations 4 of the beading tool 1 used.

[0058] It is in Fig. 5B that the holding diameter has already approached the minimum diameter of the housing part, ie the solid contour is closer to the dashed line in Fig. 5A, as this in Fig. 5A is the case. The holding diameter is preferably measured (without an explicit representation) to the opposite, not shown, side of the respective housing part 10.

[0059] The Fig. 5B to 5F preferably represent snapshots of a beading according to the invention, wherein the housing part 10 - possibly by several revolutions of the beading wheel on the housing part 10 - is continuously deformed and thereby provided with more and more depressions 5. The surface of the indentation 6 is in Fig. 5F - in contrast to Fig. 5A - correspondingly enlarged, so that a plastic deformation of the material of the housing part 10, in particular at the edge of the indentation 6 in the state of the housing part from Fig. 5F can be significantly prevented.

[0060] In the Fig. 5E and Fig. 5F, for example, the solid and dashed contours overlap, so that the dashed contour is no longer visible. Accordingly, the springback of the housing part 10 is also prevented (see above). Furthermore, as described above, a thinning of the material at the edge of the recess 6 can be counteracted (see Fig. 2A and Fig. 2B).

[0061] For example, the diameter of an electrode stack can be 22.2 mm. After the electrode stack has been inserted into a housing part and a conventional beading wheel has been pressed against the rotating housing part, for example, in a suitable device for beading, the holding diameter (see above) can be 22.6 mm. This means that the holding diameter has increased by 0.4 mm during the relaxation described above. The housing part 10 has preferably or usually become approximately 0.2 mm longer.

[0062] After using the beading wheel according to the invention (cf. Fig. 3) A holding diameter of 22.4 mm can be measured. This means that the holding diameter only increased by 0.2 mm during relaxation.

[0063] To achieve a more even beading, the corresponding housing part can be reworked with a conventional or standard beading wheel to create smaller protrusions. With this "rework," the retaining diameter can be further reduced to 22.3 mm.

[0064] Due to the small linear expansion of the housing part, the housing part according to the invention can also be provided with a double bead, i.e., two axially offset indentations, without, as mentioned above, the axial fixation of the electrode stack being released or loosened again by the impression of the second indentation. According to the invention, such double beading processes or beadings can lengthen the housing parts by less than 0.1 mm. The holding diameter can be 22.4 mm, as in the above-mentioned example.

[0065] Before a beading according to the invention, the beading tool can be further deburred in order to achieve better results and / or a more uniform beading.

[0066] Further advantages of the proposed beading include the possibility that the diameter of the electrode stack or capacitor winding is not restricted by the treatment or beading process, unlike an electrochemical cell or capacitor that has been beaded with a compression bead. This allows the internal volume of the housing part to be used more efficiently because no minimum beading depth is required to achieve plastic deformation. Furthermore, the mechanical stability of the electrochemical cell in the longitudinal direction is maintained, for example, in contrast to a compression bead.

[0067] Furthermore, the indentation can ultimately penetrate deeper into the coil because the risk of damage depends on the beading depth (see minimum diameter above) during beading and not on the final state of the bead (see holding diameter above). This means that with the same risk of damage, the bead according to the invention can penetrate deeper into the electrode stack. If the beading depth is set too low, so that, for example, no counterforces act from the electrode stack, the bead surface can become relatively smooth after several revolutions. However, if the beading tool or beading wheel is set too deep, very high forces act between the electrode stack and the beading wheel and the material will inevitably shift to the grooves of the beading wheel. In this case, the bead surface will not be smooth even after several revolutions.This means that the bead surface contains information about the forces exerted by the electrode stack and thus provides an indication of whether the bead depth was or is correctly adjusted. By continuously measuring the "gloss factor" or the reflectivity of the housing part, the bead depth can be controlled so that the optimal bead depth is always achieved, even with varying electrode stack diameters.

[0068] Before the infiltration, an electrode stack 20 (see Fig. 1A to 1C) are inserted into the housing part 10 so that, during the infiltration, the electrode stack is fixed to the housing part 10. The process step can be Fig. 5A (bead 6 with smooth surface) may already be carried out without the electrode stack being inserted into the housing part 10.

[0069] Furthermore, within the scope of the present application, it is provided that the housing parts of the electrochemical cells are provided with a plurality of beads or indentations according to the invention. The beads presented can also be combined with compression beads. For example, multiple beads have the advantage of better thermal coupling between the electrode stack and the housing part, whereby the AC load capacity can also be advantageously increased, particularly in combination with a heat sink, preferably comprising aluminum. The layer of the heat sink, which is effective for high thermal conduction, is preferably made of aluminum (Al). However, this layer can also be formed from an electrically insulating material with good thermal conduction properties.

[0070] A composite material suitable for forming heat sinks, preferably an aluminum adhesive tape, can be provided, for example, as a tape comprising a carrier layer made of Al (Al foil) and an adhesive layer applied thereto. Alternatively, it is possible to provide a heat sink in the form of an Al tape with an adhesive layer in sections, e.g., at at least one end of the tape. An aluminum adhesive tape can be provided, for example, with a total thickness of 40 to 60 micrometers. The thickness of the adhesive layer is, for example, 10 to 50% of the total thickness of the aluminum adhesive tape.

[0071] The housing part can be provided with the indentation according to the invention, for example by means of a single beading tool or beading wheel according to the invention.

[0072] Alternatively, the following sequential process steps can be provided: - Beading with a beading tool with a smooth surface and without elevations according to the invention, for example until the housing part touches the electrode stack, - Beading with a coarse-structured beading tool to avoid the aforementioned longitudinal expansion of the housing part, and - Beading with a finely structured beading tool to minimize the springback of the housing part

[0073] Furthermore, the housing part can be provided with a slightly pronounced bead during its manufacture, which still allows the electrode stack to be inserted. This bead can then be deepened after insertion or assembly using a beading wheel as described above, so that the electrode stack can be secured without extending the housing part.

[0074] The invention is not limited by the description based on the exemplary embodiments. Rather, the invention encompasses any novel feature and any combination of features, including in particular any combination of features in the patent claims, even if this feature or combination itself is not explicitly stated in the patent claims or exemplary embodiments. List of reference symbols 1 beading tool 2 Contact surface 4 Survey 5 Deepening 6 indentation 8 survey areas 10 Housing part 20 electrode stacks 21 electrode foils 100 Electrochemical Cell L length B Width KB Contact Area BR direction of movement X main axis

Claims

[1] Beading tool (1) for beading a workpiece (10), wherein - the beading tool (1) has a contact surface (2) which is designed to interact with the workpiece (10), wherein the contact surface (2) has a plurality of local, mutually delimited elevations (4), - a dimension of the elevations (4) is smaller than a width of the contact surface (2); the elevations (4) are randomly distributed and / or irregularly arranged. [2] Beading tool (1) according to claim 1, wherein the elevations (4) have elevation surfaces (8) with a surface area between 0.1 mm 2 and 1 mm 2 have. [3] Beading tool (1) according to one of the preceding claims 1 or 2, wherein the distance between adjacent elevations (4) is greater than 0.5 mm. [4] Beading tool (1) according to one of claims 1 to 3, which is a beading wheel or a beading roller. [5] Housing part (10) for an electrochemical cell (100), which defines a cavity and has at least one indentation (6), wherein a plurality of local depressions (5) are randomly distributed and / or irregularly arranged in the indentation (6), wherein a dimension of the depressions (5) is smaller than a width of the indentation (6). [6] Housing part (10) according to claim 5, wherein the indentation (6) extends over the entire circumference of the housing part (10). [7] Housing part (10) according to one of claims 5 or 6, wherein the indentation (6) is a first indentation, and wherein the housing part (10) has a second indentation (6) arranged axially offset from the first indentation (6). [8] Electrochemical cell (100) comprising a housing part (10) according to one of claims 5 to 7, wherein an electrode stack (20) is arranged in the housing part (10), and wherein the at least one indentation (6) fixes the electrode stack (20) relative to the housing part (10). [9] Electrochemical cell (100) according to claim 8, which is designed according to an electrolytic capacitor (100), wherein the electrode stack (20) is a capacitor winding comprising electrode foils (21) and an electrolyte in contact with the electrode foils (20). [10] Method for treating a housing part (10) with the following steps: - Providing a housing part (10) and a beading tool (1), - Providing the housing part (10) with a bead (6) by means of the beading tool (1) such that a plurality of local, mutually delimited depressions (5) are formed in the bead in a randomly distributed and / or irregularly arranged manner, wherein a dimension of the depressions (5) is smaller than a width of the bead (6). [11] Method according to claim 10, wherein, when providing the housing part (10) with the bead (6), in a first processing step by means of a coarse beading tool (1) a contour of the bead (6) and / or the depressions (5) is embossed into the housing part (10) and in a subsequent processing step by means of a fine beading tool (10), the depressions (5) are defined. [12] A method for producing an electrochemical cell (100), comprising: prior to providing the housing part (10) with the bead (6) according to one of the two preceding claims, providing an electrode stack (20) and inserting the electrode stack (20) into the housing part (10), wherein the electrode stack (20) is fixed in the housing part (10) by providing the bead (6). [13] Method according to claim 12, wherein after inserting the electrode stack (20) into the housing part (10), the housing part (10) is first deformed until the housing part (10) touches the electrode stack (20), and wherein the housing part (10) is then provided with the bead (6).

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